Tracker.



T. P. BRUWN.

TBAOKER. APPLIoATIon num rms-.11, 19u.

Patnted Dec. 12, 1911.

. Lm, Mw.

STATES XTENT OFFICE.

"HEODRE iP. BRO'W'N, 0F VORCESIER, MASSACHUSETTS, ASSIGNOR TD SIMPLEXPLAYER ACTION' (10.. OF VORCESTER, MASSACHUSETTS, A CURPORATION 0F MAS-SACEUSETTS.

TRACKER.

Specification of Letters Eatent.

Applicatfon filed February 11, 1911.

Patented. Deo. 12, 1911.

serial No. 698,122.

To all 'whom 'it concern:

Ble it known that. l', Tnnononn P. B i:mvn, al citiaeiibf the UnitedStat-es, residing at TVorcesterg in tthfe 'county of Worcester and"Stateva not 'Massachusetts have invented a.

iew'andfu'sful Tracker, of which the fol- 16W ,ing 'is' anspeeitatifon.

" .Th'isfilv ventifirrel tes to that class of pnena'ticf'musicalinstruments in which e rforated niusid'sheet travels over a trackeravving' openings therein through which the 'riisfdirected'atki thVpneumaticr for operilting instrument.

' "fAs'swfvellknorvn, owing to the contraction and' expansion of thesheet and other '(Sf'laiilses, ',the I'nusicV sheet frequently wanderstne side' or` 4they other f the line along "Ytrlldhit'is supposed totravel. This results in bringing the perforations in the -n'nlsiicV"Slieet'slif'gl1tly out of registration with the' holes in' the trackerand where the 'sheet Wanders'e great distance it results 'inVrestrict.ingthe opening provided by the registration of .the musicsheet perforations the tr'cler" ducts, thus interfering 'Y'vitlif theeffect V"produced So far as l'. am `vaware: theonlyineans which has beenprofefatieae'sa Further objects and advantages of the invention willappear hereinafter.

Reference is to be had to the accompany ing drawing in whichn,

Figure l is a plan on enlarged scale of a musical instrument, trackerconstructedin accordance with this invention showing how the musi-c.sheet travels thereover. Fig. 2 is a further enlarged plan of a portionof the tracker, and Fig. 3 is a diagrammatic View on the same scale asFig. 2 showingihe effect when the music sheet. wanders to one vside andalso showing in dotted lines the position of ordinary tracker holes toillustrate the dillerence in effect when the sheet Wanders. Theinvention is shown as applied to van instrument hav-inge, tracker Aoverv which a music sheet B is adapted tortravel in a well known way.The music sheet is pro-y vided with the usual perforations B. Thetracker instead of being provided with square ducts is shown as providedwith openings or ducts A having a main portion of a width not less thanthe width of the music sheet perforations B and hav:` ing an extensionA2 on each side projecting beyond the bod)v portion and adapted to beuncovered by the music sheet perforations :1s the same travels over thertracker. 'l'hesc extensions of' each hole are shown as on the saine sideof the tracker. This results in getting a maximum arca of trackeropening withoutincreasing the real space which the duets take up.lVliile this is a gei'ieral description of the shapeof the trackerducts, it will be observed by inspection of the drawings that theypreferably are made of the shape of a trapezoid and arranged so that thebase of each one is arranged on the opposite side of the tracker fromthe base of the two adjacentopenings so that the tracker ducts arealternatelyar.- ranged valong tl e tracker.;. Eiinthgimre A were'dubitare s een 's afft; higiene e case the long side of the trapezoidalo 4ening can be made substantially one-nint of In other words, it issubstantially equal to the shortest distance between the two adjacent oenings on opposite sides thereof. The o -set will amount in theseproportions to about one-sixtieth of an inch which will not affect thetime of theV sounding of the notes sufficiently to be observed. Tofurther explain the position and relative location of these openings, itmay be said that the bridges or spaces A8 between them are obli ue tothe direction of travel of the music si eet and that they arealternately arranged. They are of the same width as in the case ofsquare ducts, that is, wide enough to provide room for the walls of thelead tubes C on the back of. the tracker. Thisgenerally is abouti/27' ofan inch. From this arrangement it results that when the music sheetproperly tracks, as is indicated in Fig. 1, the offsets A2 are not brouht into operation but the instrument wili ge played with the same eifectas would be the case with the square tracker holes. If, however, thesheet wanders to one side as indicated in Fig. 3, which shows an amountof wandering greater than usually takes place, the extensions Azx willhave the eii'ect of widening the openings which are -uncovered by theperforations so that a' more nearly perfect sounding of the notes willbe the result. This is to be compared with the effect when square holesin the tracker are' used, as shownin dotted lines 'in Fig. 3. Inthatncase, with the amount of wandering indicated in that figure, thewidth of the opening uncovered by the mu- -sic sheet perforations wouldbe not over two-thirds of that uncovered in case of the presentinvention. On account of the tra ezoidal shape of the openings, and oftie fact that the extensions are on both sides of the center but onthesame side of the racket, it makes no diierenoe which way efsheetwanders. In either case the maxi- Enum duct opening is secured. Thisresult obtained because the width of the duct at ,the wide part issubstanti, yly equal tothe Shortest space between the two adjacentutzts.' Ili case the sheet w ders enough to alldtv each perforation B-to overlap the duct A at the side, itiwill 'let only a little air into.that channel and as these channels are bled anyway, it will practicallynot wish to be limited strictly thereto, butl/Vhat I doclaim is 1. Apneumatic musical instrument hav- 1ng a tracker provided with ducts overwhich a perforated musicsheet is adapted to pass, lsaid ducts havingequal s aces between them, each duct having a imension longitudinally ofthe tracker substantially equal to the shortest distance between the twoducts on opposite sides of it. 2. A pneumatic musical instrument Yhavmga tracker provided with ducts over which a perforated music sheet isadapted to pass, said ducts having equal spaces betweenthem, each ducthaving a wide and a narrow art in the face of the tracker, the wide partmg substantially as wide as the shortest distance between the two ductson opposite sides'of it. 3. A pneumatic musical instrument having atracker providedv with ducts over which a perforated. music sheet isadapted to pass, each duct having a main portion of a width not lessthan the width of the music sheet perforations and having a continuousextenslon on eachside, said extensions of each duct being. on the sameside of .the tracker.

4. A pneumatic musical instrument havwhich a perforated music sheet isadapted to pass, each duct having a main portion of a width not lessthan the width of the music sheet perforations and having a continuousextension on each side, the extensions of each two adjacent ducts beingon the opposite sides of the center of the tracker. 5. A pneumaticmusical instrument havmg a tracker provided iwith ducts over whichaperforated., music= sheet is adapted to pass, the 4spaces on the faceof the tracker between said ducts being oblique and extending indirections, alternately to the right and left' of the direction oftravel of the music sheet. i

(i. A pneumatic musical instrument having a tracker provided withfductopenings instrument` tracker having duct openings' 180 on its surfacewider at one part than at therealong, each alternate one of said rowanother in the direction of the length of the being transversely offsetwith respect to the tracker. A others.

9. .A pneumatic musical instrument hav- In testimony whereof I havehereunto set 15 5 ing a tracker provided with duct openings my hand, inthe presence of two subscribing of trapezoidal shape, the Wide basesthereof witnesses. beingalternately arranged, and each alternateopeningbeing transverse'ly'ofset.

10. AST an article of manufacture, a Witnesses: 10 tracker for a peumatic musical instrument ALBERT E. FAY,

having in' its ace a row of duct openings C. FORREST WEssoN.

TIIEODORE P. BROWN.

